Edge 510 Course Problems (Ver 2.70)

Just purchased a Garmin Edge 510 cycling computer....It's been pretty good until I tried creating and following courses on it.

I've tried different methods:

Create Course in Garmin Connect and download to 510

Drop GPX File into 510 directly and have unit create course.

Create course on 510 from a previous ride stored on unit.

All goes great until I try to follow the course and I get an error message: "Route Calculation Error". You see the trace of the route on the map but the unit does not navigate properly. This pretty much makes this feature useless.

Maybe, I was a little too quick to judge. Followed a previous ride last night and the 510 seemed to alert me when I was on or off course, so it is partially working. It's missing prompts and other info that usually shows up.

So courses seem to be partially working even if there is the error message. Still not fully trusting it until I do a few more test runs.

I just recently started using the Course feature on my 510. I have seen that error message at the start of several rides, probably 3 out of 4 attempts so far. But, I haven't had any problems following the course once I get past that screen.